How To Fix DD_CDS_ANALYSIS101 - Association &3 is used redundant, it is used in &1 and &2.

DD_CDS_ANALYSIS101 - Overview

• Message type: E = Error

• Message class: DD_CDS_ANALYSIS - CDS code inspector messages

• Message number: 101

• Message text: Association &3 is used redundant, it is used in &1 and &2.

What causes this issue?

The usage of associations in CDS path expressions is equivalent to
technical join operations in the native database view. If the same
association is in views which are stacked on top of each other,
duplicate joins are created which are potentially unnecessary. In order
to improve the performance of CDS Views duplicate joins should be
avoided.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Instead of using the same association multiple times in stacked CDS
Views it is more efficient to include all the columns required into the
CDS View at the bottom of the stack.
This warning can be suppressed by putting the pseudo comment
/*+[hideWarning] { "IDS" : [ "DOUBLE_JOIN" ] }*/
in front of one of the path expressions using the association at hand or
at the view itself.

Error message extract from SAP system. Copyright SAP SE.

DD_CDS_ANALYSIS101 - Details

• The SAP error message DD_CDS_ANALYSIS101 indicates that there is a redundancy in the use of an association in a Core Data Services (CDS) view. Specifically, the error message states that an association (denoted as &3) is being used redundantly in two different places (denoted as &1 and &2) within the same CDS view or between different CDS views.
  
  Cause:
  This error typically arises when:
  
  An association is defined in a CDS view and is being referenced multiple times in a way that is not allowed.
  The same association is being used in a manner that creates ambiguity or redundancy, which can lead to confusion in the data model.
  
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Review the CDS View Definition: Check the definition of the CDS view where the error is occurring. Look for the association that is mentioned in the error message.
  
  
  Identify Redundant Usage: Determine where the association is being used redundantly.